Ranking the 64 NCAA Women's Teams on the Conference-Adjusted Combined Offensive-Defensive (CACOD) Metric

With the NCAA Division I women's volleyball tournament scheduled to begin play on Thursday, I am unveiling my second annual ranking of the tournament teams on the Conference-Adjusted Combined Offensive-Defensive (CACOD) metric. Though the CACOD is extremely simple to calculate (see below), it held its own with the more established volleyball ranking systems (e.g., Pablo, RPI, Rich Kern) in predicting match outcomes of last year's women's NCAA tournament.

In fact, only three quantities go into the CACOD formula: a team's hitting percentage for the entire season, the hitting percentage the team allowed its opposition to achive (cumulatively) on the season, and a conference-difficulty factor that I determine. I wrote last year about hitting percentage being "a great singular statistic for incorporating many aspects of the game." As I elaborated:

If you hit well (not just keep the ball in play, but get kills), your (individual or team) hitting percentage goes up. An attack kept in play by the other team hurts, as does a hitting error (spiking the ball out of bounds or getting stuff-blocked for an opponent's point). In order to hit well, a team must pass and set well. If you block or dig your opponent's spike attempts, that drives down the opponent's hitting percentage.

Another reason, I suspect, that the CACOD appears to work well is the sheer volume of data that goes into determining hitting percentages. A typical team might take (and have its opponents cumulatively take) from 3,500 to 4,500 swings in a regular season. The formula for the CACOD is simply:

A more in-depth explanation of my ranking scheme is available from a year ago's posting, when I introduced the system. My conference-difficulty factors are as follows:

Factor	Conferences
1.25	Big 10, Pac 12
1.20	Big 12
1.10	ACC
1.00	SEC, Big East*, Atlantic 10, Mid America, Missouri Valley, West Coast, Big West, Mountain West, Western Athletic (WAC), Conference USA
0.75	All Others

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*The American Athletic Conference, a spin-off from the Big East, will have a factor of 1.00.

The idea behind the conference-difficulty weighting factor is that, if a team did well on the two primary measures (hitting at a high percentage and keeping the opponents' hitting percentage low) in a tough conference, it should receive some "extra credit." Conversely, if a team did well in a relatively weak conference, its statistics should be discounted somewhat.

This year's factor weights (above) are very similar to last season's, except for two changes. I lowered the Big 12 slightly, from 1.25 to 1.20, as this year's version of the conference seemed a little down from last year (with Texas A&M having departed and a not-ready-for-prime-time West Virginia squad moving in). Also, I raised the ACC from 1.00 to 1.10, in light of some recent NCAA-tourney success (Florida State making the Final Four a year ago and the Elite Eight in 2009; and Duke making the Elite Eight in 2010).

Here are the resulting rankings (see "adjusted ratio" in the right-most column). In any match, whichever team has the higher CACOD ranking would be expected to win, under my system. You may click on the graphics to enlarge them (note that the rankings appear in three parts).

Whereas my ranking of Penn State, Texas, and Stanford in the top three closely matches the actual tournament seedings, the CACOD offers some surprises. Whereas BYU is seeded 12th, for example, I have the Cougars as the fourth-best team in the field. Whereas Florida is seeded 14th, I have the Gators seventh.

Was the CACOD just lucky last year or will it be a successful predictor two years in a row? We'll have a pretty good idea after the next three weekends of tournament play!

Bruin OH's Kidder and Love Play Regular-Season Finale as Trojans Visit UCLA

Defending NCAA champion UCLA hosts USC in the Bruins' regular-season finale tonight, marking the final pre-tournament home appearance for UCLA seniors Rachael Kidder, Tabi Love, and Bojana Todorovic. Outside hitters Kidder and Love have been the mainstays of the UCLA offense. Accordingly, I decided to examine the Bruins' win-loss records this season when Kidder alone, Love alone, both of them, or neither of them had strong hitting nights.

I chose a .300 hitting percentage to define "strong" hitting. Volleyball announcers often make an analogy to baseball hitting, saying that a .300 average in either sport is a sign of success. Also, using .300 as the dividing line breaks UCLA's 28 matches into mostly equal-sized groups. My analysis is summarized in the following graph, on which you can click to enlarge.

The blue bar shows that when Kidder and Love both hit .300 or better in the same match, the Bruins are a perfect 8-0 (1.000 winning percentage). The only problem is that none of these matches were against elite opponents in the Pac 12 (Stanford, USC, Washington, or Oregon). The success in these matches of Kidder, Love, and the team as a whole may thus reflect relatively weak opposition.

The orange-yellow bar tells us that the Bruins were 7-1 (.875) when Love (but not Kidder) hit in the .300s or above. These matches include a win at Hawai'i and a narrow loss at Nebraska.

The pale-yellow bar reveals that when Kidder (but not Love) reached or exceeded .300, UCLA was 3-1 (.750). This batch includes the Bruins' lone win (thus far) against an elite conference opponent (vs. Washington, in Los Angeles) and a narrow loss at Stanford.

Finally, the grey bar shows that when Kidder and Love both hit below .300, the Bruins are 3-5 (.375). More ominously for UCLA, the three wins in this category all came against lesser competition (Colorado, Northeastern, and UC Santa Barbara). The five losses, on the other hand, were all against top Pac 12 opposition on the road.

As the Bruins take on USC tonight and then move on to the NCAA tourney, UCLA's coaches and fans naturally will want Kidder, Love, and all their teammates to hit as effectively as possible. However, last year's Bruin squad showed that stellar hitting percentages from Kidder and Love were not essential for winning a national championship. In UCLA's NCAA final win over Illinois, Love hit .294 (14 kills and 4 errors in 34 attempts) and Kidder hit .127 (20-11-71). The Bruins hit only .218 overall, but held the Illini to a .215 hitting percentage.

Wild Weekend in the Pac 12

An amazing finish in the Oregon at Washington match and a resurgence by USC against the northern California schools are the big stories in this weekend's Pac-12 play.

The Huskies fought off no fewer than 14 match points to defeat the Ducks, 26-24, 16-25, 21-25, 32-30, 25-23. Keeping in mind that fifth games are to 15 points, we see how deeply into overtime the decisive set went. Two of the match points were in Game 4 and 12 were in Game 5. As the linked article notes, "Making the run all the more impressive was that it came without UW's offensive leader, sophomore Krista Vansant, who landed awkwardly and suffered what appears to be a sprained ankle early in the fourth set, and did not return to the match."

Several players were able to maintain hitting percentages of .300 or better over a large number of attempts (box score). For Oregon, they included Liz Brenner (.410; 22 kills and 6 errors on 39 attempts) and Alaina Bergsma (.302; 31-12-63). For Washington, they included Cassie Strickland (.394; 14-1-33), Kylin Munoz (.342; 17-4-38), and Gabbi Parker (.308; 9-1-26).

A Husky forte all season has been the block and last night's match was no exception, with U-Dub exceeding Oregon in total team blocks, 19-6. The Ducks dominated digging, however, 83-54.

***

Down in Los Angeles, USC handed Stanford its first conference loss, 25-19, 25-20, 27-29, 25-22, on Thursday night. The Trojans then followed up on Friday with a five-set victory over Cal, 23-25, 25-21, 18-25, 29-27, 15-11.

As the above-linked game article from the Cardinal-Trojan match-up points out, "Neither team would let the ball drop as USC recorded a season-high 112 digs and Stanford had 117. Junior libero Natalie Hagglund had the most impressive night of all as she etched her name into the Trojan record books with a career-high 44 digs."

Based on the Stanford-USC box score, I created the following pie-chart (on which you may click to enlarge) to show what happened to each of Stanford's 203 spike attempts on the evening.

What we see is that the Trojans dug up 55.2% of Stanford's total spike attempts (112/203), and 62.6% of the Cardinal's non-error attacks (112/179). The metric of non-error attacks is useful because the defense cannot be expected to dig opposing spike attempts that are blocked at the net or hit out-of-bounds. Not surprisingly given the above data, Stanford had a poor night in terms of hitting percentage, registering a .187. (The figure in the pie-chart of 17 balls hit out-of-bounds by the Cardinal comes from subtracting the 7 USC blocks from Stanford's total of 24 hitting errors; miscellaneous would include balls blocked back over the net by USC that Stanford was able to keep in play, for example.) 

USC's digging two nights ago against Stanford represents a big improvement over some early-season matches. As I wrote about in this late-September posting, the Trojans had dug only 37% of Oregon's non-error attacks and 46% of UCLA's in a pair of key matches at that point in the season. In the first USC-Stanford match of the season (October 10), a 3-0 Cardinal sweep, the Trojans dug only 43% of Stanford's non-error attacks (39/[100-9]).

USC's main offensive weapon, frosh outside hitter Samantha Bricio, also improved her performance from the first (-.043; 10-12-47) to the second (.226; 19-5-62) Stanford match. Also, in the second match, Trojan middle blockers Alicia Ogoms (.471; 8-0-17) and Alexis Olgard (.444; 12-0-27) came through with big hitting nights.

***

Stanford rebounded to defeat UCLA in four games (25-22, 25-18, 15-25, 27-25) Friday night, as the renovated Pauley Pavilion was opened for volleyball. The Cardinal received strong hitting performances from Inky Ajanaku (.412; 10-3-17), Rachel Williams (.400; 16-4-30), and Carly Wopat (.346; 11-2-26). One-half of UCLA's outside-hitting duo, Rachael Kidder, hit well (.362; 21-4-47), but the other half, Tabi Love, had a tough night (.038; 10-8-52).

Michigan Hitting Attack Comes Alive

For most of this season, I haven't had much to write about my graduate-school alma mater, the University of Michigan. Over their last five matches, however, the Wolverines have been playing their best volleyball of the season. They are 5-0 during this stretch, including wins over then-No. 4 Nebraska and then-No. 10 Minnesota (game-by-game log).

Michigan has greatly elevated its hitting performance during these matches, as shown in the following graph (on which you can click to enlarge). The graph depicts the hitting percentages for four leading Wolverine hitters (different shades and styles of blue), and the team as a whole (yellow), in all of the team's conference matches to date.

The first thing to notice is that, until the recent hot streak (indicated by the red arrow), Michigan as a team had hit at or below .200 in most of its matches, a fairly anemic level. In its five most recent matches, in contrast, Michigan's hitting percentages have ranged from .298 to .460. Even with their much-improved offensive performance of late, the Wolverines are still hitting only .234 in Big 10 play as of this writing, ranking them eighth in the conference in team hitting percentage.

Junior middle blocker Jennifer Cross (dashed dark-blue line) has performed steadily at a high level, recording a higher hitting percentage than the team as a whole in nearly all the Wolverines' conference matches. Senior right-side hitter Claire McElheny (dashed light-blue line) has been up and down all season. However, lately she's been entirely up, hitting .571 (9 kills with 1 error on 14 attempts) vs. Iowa, .522 (14-2-23) vs. Wisconsin, and .900 (9-0-10) vs. Minnesota.

Lexi Erwin is far and away the Wolverines' most frequent hitter, with her 627 total attempts to date in conference play exceeding the next closest player, Molly Toon, by 268 swings. Both are junior outside (left-side) hitters. Erwin (solid dark-blue line) was somewhat inconsistent early in Big 10 play, but has been mostly on an upswing in the second half of the conference season. Toon (solid light-blue line) struggled for most of the conference schedule, but has improved her hitting output in the last five matches.

Michigan got hot at the end of last season and made a nice run in the NCAA tournament, sparked by then-senior OH Alex Hunt. It apparently has taken this year's Wolverine squad some time to adjust to Hunt's absence, but the team's recent offensive statistics look promising. The bulk of Michigan's recent hot streak has come at home. For the final two weekends of the regular season, the Wolverines play entirely on the road, at Northwestern, Illinois, Michigan State, and Ohio State.

Nebraska Slumping of Late

Perennial power Nebraska heads into this weekend's homestand vs. Indiana (tonight) and Purdue (tomorrow) with three losses in its last four matches. After dropping their Big 10 opener at Penn State -- certainly no crime -- the Cornhuskers won nine straight. The next time out, seemingly out of nowhere, Nebraska fell at home to Ohio State in four games, before rebounding to beat then-No. 1 Penn State in five. A winless trip to Michigan and Michigan State followed, with the loss to the Wolverines particularly jarring because the Huskers had led two games to none.

The Huskers' season to date is nicely encapsulated in this weekend's match notes from the Nebraska athletic department. Given the importance of hitting percentage in teams' success, I decided to plot Nebraska's hitting percentages for all of its conference matches so far this season, for the team as a whole and for the five players who take the most swings (you may click on the following graphic to enlarge it). 

During the recent slump, the Huskers as a team, and Gina Mancuso, Hannah Werth, and Hayley Thramer, individually, have seen a sharp decline in their hitting percentages (highlighted in yellow). Frosh middle blocker Meghan Haggerty has been erratic throughout the Big 10 season, recording some big highs (.700 at home vs. MSU, .778 at Illinois) and lows (-.111 at home vs. Wisconsin) in her hitting percentages.

In fact, Mancuso has been an almost perfect barometer of how the team is doing. When she's hit well, so have the Huskers, and when she's hit poorly, the team has, as well. To simplify things, I've removed the other players from the above graph and created a new plot below. One can see that, other than the Wisconsin match, in which Mancuso exploded for a .583 performance, her hitting percentages (dotted red line) have tracked extremely closely with the team's hitting percentages (black line). In most Big 10 matches, Mancuso has taken from 20-30% of the Huskers' swings.

Upset Friday!

Last night saw four major upsets, three of which were in the Pac 12. All four of the victorious teams were unranked in the latest AVCA national poll. No. 2 Oregon lost at home in five to Cal, No. 4 Nebraska squandered a two-games-to-none lead and fell at Michigan, No. 5 UCLA was swept at Arizona, and No. 6 USC was swept at Arizona State.

UCLA really seems to have a hard time with Arizona, for whatever reason. Even though the Bruins ultimately won last year's NCAA title, they lost both 2011 regular-season matches to the Wildcats. This year, the teams split, with UCLA winning at home on October 7, before last night's Arizona win. In order to get an idea of what might be going on, I've created the following table of key statistics for the last four matches between the Bruins and Wildcats (box-score links are at the top of each column; H% = hitting percentage). My usual warnings about concluding too much from small samples apply, however. 

	2011@Ariz	2011@UCLA	2012@UCLA	2012@Ariz
UCLA Team H%	.256	.189	.333	.143
Kidder H%	.290	.265	.333	.148
Love H%	.167	.050	.591	.133
UCLA Side-Out%	62%	62%	68%	54%
Arizona Team H%	.239	.259	.258	.288
Arizobal H%	.263	DNP	.267	.312
Kingdon H%	.200	.061	.278	.219
Arizona Side-Out%	57%	70%	55%	66%
Winner	Ariz 3-2	Ariz 3-0	UCLA 3-0	Ariz 3-0

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Arizona seems to be the steadier team in these matches on hitting percentage, staying within a range of .239 to .288, whereas UCLA's been all over the place from .143 to .333. The attacking prowess of Bruin outside hitter Tabi Love appears to be crucial; in UCLA's one win, Love hit .591 (13 kills without an error on 22 attempts), whereas in the other matches, she's hit .167 and below.

Sophomore outside hitters Taylor Arizobal and Madison Kingdon were steady for the Wildcats in this year's matches against the Bruins. Last year, U of A had seniors Cursty Jackson and Courtney Karst to handle a lot of the hitting load and let Arizobal and Kingdon come along gradually. For example, in Arizona's second 2011 match against UCLA, Jackson hit .304 and Karst, .393, to key the Wildcat sweep.

I don't know that UCLA's side-out rates are that diagnostic, other than the 54% performance associated with last night's loss. In the teams' first 2011 match, the Bruins had the better side-out rate despite losing the match (thanks to an 80-31% side-out advantage in Game 2, which the Bruins won 25-10). Also, when the Wildcats have sided-out at 66% or better for a full match, the Bruins haven't been able to win even a game.

***

Nebraska has gone through an unusual stretch recently. Last weekend, playing at home, the Huskers lost to Ohio State, but bounced back to beat No. 1 Penn State. Nebraska, of course, lost last night to Michigan and now is playing Michigan State. I will elaborate upon  Nebraska's recent performance, as well as that of USC and Oregon, in future postings.

Hitting Charts for Washington vs. USC/UCLA

This past weekend, the University of Washington women went down to Los Angeles where they lost matches to USC (in five games) and UCLA (in four). Both matches were televised on the Pac 12 Network, so I was able to compile hitting charts for selected games from both matches. You may click on the following graphics to enlarge them.

My notation and terminology are evolving as I create these diagrams. One recent development is that, if you see "IP" only, it means a hit attempt was kept in play due to being dug, whereas IP accompanied by "b reboot" means that the hit attempt was blocked back to the attacking team, which had to start over with a new attack. As I have noted previously, I'm doing my best to identify the player who took each spike attempt, but sometimes I'm only able to identify the team of the attacker. First, we have Game 4 of the USC-Washington match...

Next, we have two diagrams for Games 3 and 4, respectively, of the UCLA-Washington contest...

One trend apparent in the above charts (albeit with small sample sizes) is that Washington appears to be moving around its main offensive weapon, outside hitter Krista Vansant, from her usual location on the left-hand side of the front row, so she can take occasional swings from the right side or even the middle, on a combination play (see the quote from the TV announcers in Game 3 of the UCLA match).

Against USC, Vansant took 80 of the Huskies' 203 attemps (39.4%), hitting .150. She doubled her hitting percentage against UCLA, reaching .305 on 59 attempts. You can compare the Huskies' hitting attempts above vs. USC and UCLA to an earlier Washington match vs. Stanford.

From the one game above featuring USC, the main pattern I'm able to glean for the Trojans is nothing earth-shattering. Specifically, they frequently called the number of frosh outside hitter Samantha Bricio. For the match as a whole, she took 74 of USC's 202 swings (36.6%), hitting .243 (box score).

In UCLA's match against Washington, the Bruins went heavily to Tabi Love on the outside. In addition, UCLA middle blockers Zoe Nightingale and Mariana Aquino hit with great proficiency, both in the depicted games and for the match as a whole; their final hitting percentages were .421 and .500, respectively (box score).

I probably won't be charting many more Pac 12 matches this season. I had been receiving the Pac 12 Network on my satellite package, which is a little unusual because I live in Texas. The Pac 12 Network no longer appears on my television, however. Perhaps it appeared during October as a free preview to entice viewers outside the Pac 12's "footprint" to subscribe.